Avocado Consumption and Risk Factors of Heart Disease: a Systematic Review and Meta‐analysis

Abstract

BackgroundAvocados contain a variety of nutrients and phytochemicals that have individually been related to cardiovascular benefit.ObjectiveTo summarize the data related to avocado consumption (whole fruit, oil) and risk for cardiovascular diseases (CVD) using systematic review and meta‐analysis.DesignMedline, Cochrane Central, and CAB databases were searched through October 2016 for all language publications on avocado intake and heart health indices. We included studies of all designs that quantified the amount of avocado intake in adults. CVD risk factors of interest included serum lipids, blood pressure, body weight, blood glucose and insulin levels, inflammatory markers, and all clinical outcomes of CVD. Studies were eligible if participants were healthy or if cardiovascular risk factors such as obesity, dyslipidemia, diabetes, or hypertension were present at baseline. The minimum duration of follow‐up for blood lipid outcomes was set at 3 weeks.Two investigators independently screened citations and extracted data. Random effect models meta‐analysis was used when at least 3 studies reported the same outcome.ResultsOf the 17 studies (449 subjects) published between 1960 and October 2016 and eligible for our review, 6 studies reported quantitative data for meta‐analyses of avocado intake versus no avocado intake, 3 studies compared avocado plus other monounsaturated fats intake with a control diet, and 8 studies reported qualitative data. The funding sources included industry (5 studies) and government/academia (5 studies) and were not reported in 7 studies. Avocado intake non‐significantly decreased serum total cholesterol (TC) (6 trials, net change −3.97 mg/dL, 95% CI −9.43, 1.50); LDL‐C (6 trials, net change −4.22 mg/dL, 95% CI −11.32, 2.89); and triglycerides (6 trials, net change −20.69 mg/dL, 95% CI −43.32, 1.94). Avocado intake significantly increased HDL‐C (6 trials, net change 3.17 mg/dL, 95% CI 0.21, 6.13); decreased TC:HDL (4 trials, net change −0.45 (95% CI −0.68, −0.22) and LDL:HDL (3 trials, net change −0.19 (−0.38, −0.01). Body weight was unchanged with avocado intake (5 trials, net change 0.19 mg/dL, 95% CI −0.20, 0.57). The differences in outcomes of blood glucose, HOMA‐IR, BMI, systolic and diastolic blood pressure were reported in <3 studies and were not significant between avocado and control groups. None of the eligible studies reported incident clinical outcomes of CVD.ConclusionReviewed studies of avocado intake were unable to show a statistically significant decrease in serum TC, LDL‐C and triglycerides levels. However, avocado intake significantly increased serum HDL‐C levels and consequently decreased TC:HDL ratio and LDL:HDL ratio, indicating a potential association between avocado intake and reduced CVD risk.Support or Funding InformationThis study was supported by the Hass Avocado Board and USDA 1950‐51000‐087